Highway crossing protection



Nov. 3, 1931. A. B. HEYES 1,829,956

HIGHWAY CROSSING PROTECTION Filed NOV. 26, 1930 I Lm A 0 a 8 C L] L B aPcK- P I 6 LOW 1 u 16 C a 1 3 2 (6 Kg 8 L "cm-1121 (omaa INVENTORI A.13. Ha yes,

BY Q & W

/ z ATTORNEY.

Patented Nov. 3, 1931 UNITED STATES PATENT OFFICE ALFRED B. HEYES, OFSWISSVALE, PENNSYLVANIA, ASSIGNOB TO THE UNION SWITCH 8t SIGNAL COMPANY,SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIA HIGHWAY,GROSEING PROTECTION Application filed November 26, 1930. Serial No.498,366.

My invention relates to highway crossing protection, that is, toapparatus for protecting the intersections of railways and highways.

I will describe one form of apparatus embodying my invention, and willthen point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view illustrating one form ofapparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate thetrack rails of a stretch of railway track over which traffic normallymoves in the direction indicated by the arrow. These track rails aredivided by means of insulated joints 2, to form a plurality of tracksections, of which only one complete section D-E is shown in thedrawing. A highway M intersects this section at a point some distance inadvance of the point D.

Section D-E is provided with the usual track circuit comprising atransformer T, the secondary 3 of which is connected across the rails atthe exit end of the section, and a track relay L connected across therails at the entrance end of the section. The primary 4 of transformer Tis constantly connected with the terminals B and G of a suitable sourceof alternating current not shown in the drawiiig.

Section E is also provided with a time element relay A, and with a.checking relay F. The time element relay A may be of any suitable type,and as here shown, is provided with the usual time element contact 6which becomes opened at the expiration of a comparatively longadjustable time interval after the relay becomes energized. Re lay A isalso provided with a checking con tact 7 which becomes closed, upondeenergization of the relay, as soon as the operating mechanism of therelay has restored itself to its normal deenergized condition, and

T which opens, upon energization of the relay,

as soon as the operating mechanism has started to function. Relay A iscontrolled by a back contact 5 of track relay L, so that relay A willbecome energized whenever track relay L becomes deenergized. Checkingrelay F is controlled by checking contact 7 of rcin lay A, and willtherefore be energized whenever relay A is deenergized, provided relay Ais operating in its normal manner.

The relays L, A and F control a slow-releasing signal relay K which, inturn, controls a highway crossing protective device of any suitabletype. As here shown, thehighway crossing protective device is anelectric bell S, which is connected with the terminals B and C of thesource over a back contact 8 of relay K, so that this bell will ringwhen ever relay K is deenergized.

Relay K is provided with a circuit which passes from terminal B throughtime element contact 6 of relay A, front contact 9 of relay L, and thewinding of relay K to'terminal C. This circuit is provided with a brancharound front contact 9 of relay L in cluding back contact 10 of relay F.

Trafiic over section DE is controlled by awayside signal J which, in theform here shown, is a light signal comprising three electric lamps G, Yand R arranged when energized to indicate proceed, caution and stop,respectively. As here shown, signal J is controlled by relays L and F,and by a distant relay H. The distant relay H, in turn, is controlledbya front contact 11 of the track relay L for the section to the rightof point E in such manner that this relay will be energized ordeenergized according as the section to the right of point E isunoccupied or occupied. 1

Lamp G of signal J is provided with a circuit which passes from terminalB through front contact 12-12- of track relay L, front contact 1313- ofchecking relay F, front contact 1414 of dist-ant relay H, and thefilament of lamp G to terminal C. When this circuit is closed, lamp G islighted and signal J indicates proceed. Lamp Y of signal J is providedwith a circuit which passes from terminal B through front contact 1212of track relay L, front contact 1313 of checking relay F, back contact14.14@ of distant relay H, and the filament of-lamp Y to terminal C.When this circuit is closed, lamp Y is lighted, and signal J indicatescaution. Lamp R of signal J is provided (ill with a circuit which passesfrom terminal B, through back contact l212 of relay L and the filamentof lamp R to terminal C. Lamp R is also provided with anotner circuitwhich passes from terminal B, through front contact 12-12 of relay L,back contact 13l3 of checking relay F, and the filament of lamp R- toterminal C. lVhen either of these circuits for lamp R is closed, lamp Ris lighted, and signal J indicates stop.

As shown in the drawing, section DE and the section to the right ofpoint E are both unoccupied. Track relays L and L are therefore bothenergized. Since track relay L is energized, time element relay A isdeenergized. The circuit for relay F is there fore closed at checkingcontact 7 of relay A, and the circuit for signal relay K is closed attime element contact 6 of relay A and at front Contact 9 of relay L.Relays F and K are therefore both energized. Since relay K is energized,the circuit for bell S is open at back contact 8 of this relay, and bellS is therefore deenergized. Distant relay H is energized, and thecircuit for lamp G of signal J is therefore closed, so that signal Jdisplays a proceed indication.

In explaining the operation of the apparatus, I will first assume thatwith the parts in the conditions ust described, a train moving in thedirection of the arrow enters section DE. This deenergizes track relayL, so that relay L opens its front contacts 9 and 1212, and closes itsback contacts 5 and 12-12 The opening of front contact 12-42 of relay Linterrupts the circuit for lamp G of signal J, and the closing of backcontact 1212 completes the circuit for lamp R. Lamp G therefore becomesextinguished, and lamp R becomes light-ed to indicate to any followingtrain that section DE is occupied. The opening of front contact 9 ofrelay L interrupts the circuit for relay K, but this circuit onlyremains open for a short interval of time, because the closing of backcontact 5 of relay L causes time element relay A to become energized,and if relay A is operating in the normal manner, contact 7 of thisrelay opens and relay F immediately becomes deenergized. to complete thebranch around contact 9 at its back contact 10. Relay K is madesuliiciently slow-releasing so that it holds its front contact 8 openduring the interval of time which elapses between the opening of contact9 and the closing of contact 10, and it will be apparent, therefore,that bell S does not become energized under these conditions. hen thetime interval for which the time element contact 6 of relay A is set,has expired. however, time element contact 6 opens, and the circuit forrelay K is then interrupted at this contact. Relay K therefore nowbecomes deenergized and closes its back contact 8 so that bell S startsto ring, thereby warning users of the highway that a train isapproaching on the railway. In actual practice, contact 6 will usuallybe so adjusted, and the parts will be so proportioned, that bell S willnot start to ring after a train has entered section D-E until the train,when traveling at the fastest speed at which it is permitted to approachthe highway, is at the minimum distance away from the highway which willpermit users of the highway to safely clear the railway.

lVhen the train enters the section to the right of point E, track relayL becomes dcenergized and deenergizes distant relay H. This has noeffect on the remainder of the apparatus under these conditions,however, because both circuits controlled by this relay are then open atfront contact 1212 of relay L. When the train has passed completely outof section D-E, track relay L again picks up, thereby closing its frontcontacts 9 and 1212 .and opening its back contacts 5 and 12-12". Theopening of front Contact 5 of relay L deenergizes relay A whichimmediately closes its checking contact 7 and its time element contact6. The closing of time element contact 6 completes the circuit for relayK, and the closing of checking contact 7 completes the circuit for relayF. Relays K and F therefore both become energized. When relay K becomesenergized, the circuit for bell S is interrupt d, and bell S thereforestops ringing. When front contact 1313 of relay F becomes closed, thecircuit for lamp Y of signal J is completed, the circuit for lamp havingpreviously been interrupted at contact 1212 when relay L becameenergized. Lamp Y therefore becomes lighted to indicate that section DEis unoccupied, but that the section to the right of point E is occupied.When the train passes out of this latter section, track relay L becomesenergized. which, in turn, energizes distant relay H. \Vhcn backcont-act 14-44: of relay H opens, it in terrupts the circuit for lamp Yof signal J, and when front contact ll-l4l becomes closed, it completesthe circuit for lamp G. Lamp Y therefore becomes extinguished, and lampG beo-mes lighted, so that the parts are then restored to the conditionsin which they are illustrated in the drawing.

I will now assume that with the parts in their normal condition, a trainenters section D-E, and deenergizes track relay L, but that time elementrelay A fails to operate, due for example, to a broken wire, or to aslmrt-circuited winding. Under these conditions, checking contact 7 oftime element relay it remains closed, and checking relay F thereforeremains energized, so that its back con tact 10 remains open. As aresult, the branch for the circuit for relay K around front contact 9 ofrelay L which normally becomes closed at contact 10 of relay F shortlyafter relay L becomes deenergized, now remains open, and relay Ktherefore closes its back contact 8 under these conditions as soon afterrelay L has become deenergized as the time interval required for thisrelay to release has expired. hen contact 8 of relay K is closed, bell Sstarts to ring, and it will be apparent, therefore, that if relay Afails to operate in the normal manner when a train enters se tion DE,bell S instead of remaining deenergized for the comparatively longinterval of time normally required for relay A to open its time elementcontact, will become energized at the expiration of the comparativelyshort interval of time necessary for relay K to release after relay Lhas become deenergized.

I will now assume that when a train enters section D--E and deenergizesrelay L, time element relay A picks up in the normal manner, and causesbell S to ring, but that, when the train has passed out of this section,the relay fails to restore itself to its normally deenergized conditionafter track relay L picks up. Under these conditions, checking contact 7of relay A remains open, so that relay F remains deenergized. Thecircuit for lamp R of signal J including front contact l212 of trackrelay L and back contact 13-13 of relay F is then closed, and lamp Ittherefore remains lighted even though distant relay H now becomesenergized due to the train having passed completely out of the sectionto the right of point E. As a result, when a following train approachessignal J it receives a stop indication, and when this signal failstoclear after a reasonable length of time, the improper operation of thetime element relay will be detected. Furthermore, relay K now remainsdeenergized, and bell S will therefore continue to ring until the timeelement relay is repaired.

It will be apparent, therefore, that with apparatus embodying myinvention, failure of the time element relay to function in its normalmanner will not cause a dangerous condition to exist at the highway.

It should be pointed out that since the time interval which elapsesbetween the deenergization of relay L and the opening of time elementcontact 6 is adjustable, the crossing signal may be made to operate atthe expiration of any desired time interval after the train enterssection D-E. This permits the apparatus to be readily adapted tosections having different distances between the entrance end of thesection and the highway, and over which trains travel at different ratesof speed, and makes it possible to control the highway crossingprotective device by '2 the usual track circuit which is employed tocontrol the railway signals without the use of cut sections or othersimilar auxiliary control means.

It should also be pointed out that, for the purpose of describing myinvention, I have scribed only one form of apparatus embodya ing myinvention, it is understood that varlous changes and modifications maybe made therein within the scope of the appended 7 claims withoutdeparting from the spirit and scope of my invention.

Having thus described my I claim is:

1. In combination, a section of railway track intersected by a highway,a track cirinvention, what cuit for said section including a trackrelay,

a time element relay controlled by said track relay, said time elementrelay being provided with a checking contact which becomes operatedimmediately upon energization of the relay and a time element contactwhich becomes operated at the expiration of a comparatively long timelnterval after the relay becomes energized, a checking relay controlledby said checking contact, a signal relay, means for controlling saidsignal relay controlled by said track relay and said checking relay andincluding said time element contact, and a crossing protective devicelocated at the intersection of said highway and said section andcontrolled by said signal relay.

2. I combination, a section of railway track intersected by a highway, atrack circuit for said section including a track relay, a time elementrelay controlled by said track relay, said time element relay beingprovided with a checking contact which becomes operated immediately uponenergization of the relay and a time element contact which becomesoperated at the expiration of a comparatively long time interval afterthe relay becomes energized, a checking relay controlled by saidchecking contact, .a signal relay, a circuit for said signal relayincluding said time element contact and a front contact of said trackrelay, said circuit being provided with a branch around said frontcontact of said track relay including a back contact of said checkingrelay, and a highway crossing signal located at the intersection of saidhighway and said section and controlled by said signal relay.

In combination, a section of railway track intersected by a highway, atrack circuit for said section including a track relay, a time elementrelay controlled bya back contact of said track relay, said time elementrelay being provided with a normally closed checking contact whichbecomes opened as soon as the relay becomes energized and with lll ,comes a normally closed time element contact which remains closed afterthe relay becomes energized until the expiration of a time interval ofcomparatively long duration, a checking relay controlled by saidchecking contact, aslow releasing signal relay, a circuit for saidsignal relay including said time element contact and a front contact ofsaid track relay, said circuit being provided with abranch around saidfront contact of said track relay including a back contact of saidchecking relay, and a highway crossing protective device located at theintersection of said highway and said sect-ion and controlled by a backcontact of said signal relay.

In combination, a section of railway track intersected by a highway, atrack circuit for said section including a track relay, a time elementrelay, means controlled by a back contact of said track relay forenergizing said time element relay, said time element relay beingprovided with a normally closed checking contact which opens immediatelyupon energization of the relay and with a normally closed time elementcontact which becomes opened at the expiration of a comparatively longtime interval after the relay beenergized, a slow releasing signalrelay, a circuit for said signal relay including said time elementcontact and a front contact of said track relay, means controlled bysaid checking contact for shunting said front contact of said trackrelay upon energization of aid time element relay, said signal relaybeing sulilcicntly slow releasing to bridge the inte val of time whichnormally elapses between the opening of said front contact and theoperation of said shunting means, and a highway crossing signal locatedat the intersection of said highway and said crossing and (controlled bya back contact of said signal relay.

5. In combination, a section of railway track intersected by a highway,a track circuit for said section including a track relay, a time elementrelay controlled by said track relay and arranged to become energizedupon dccnergization of said track relay, said time clement relay beingprovided with normally closed contact which becomes opened at theexpiration of a predetermined time interval after the relay becomesenergized, a slow releasing signal relay controlled by said time elementcontact and a front contact of said track relay, means controlled bysaid time clement relay and effective when said time element relaybecomes energized for normally bridging said front contact of said trackrelay before said slow releasing relay has become deenergized, and acrossing protective device located at the intersection of said highwayand said section and controlled by said signal relay.

6. In combination, a section of railway track intersected by a highway,a track circuit for said section including a track relay, a time elementrelay controlled by said track relay, a checking relay controlled bysaid time clen'ient relay, a signal relay controlled by said timeelement relay and said track relay as well as by said checking relay, acrossing protective device located at the intersection of said highwayam said section and controlled by said signal relay, and a signal for dsection controlled in part by said checking relay.

7. in combination, a section of railway track intersected by a highway,a track circuit for said section including a track relay, a time clementrelay controlled by a back contact of said track relay, said timeelement relay being provided with a normally closed checking contactwhich becon'ies opened as s on a the relaybcco1ncs-z energized and witha normally closed time element contact which reu'lains c osed after therelay becomes energized until the expiration of a time interval ofcmnparatirely long duration, a checking relay controlled by saidchecking contact, a slow releasing signal relay, a circuit for said rialrelay including said time OlClIlOIlt contact and a front contact of saidtrack relay, said circuit being provided with a branch around said frontcontact of said track relay ncluding a back contact of said checkingrelay, a highway crossing protective device located at the intersectionof said highway and said section and controlled by a back contact ofsaid. signal. rel y, and a signal. for said section co 'olled in part bysaid checking relay such n'ianner that when said checking relay iseeuergized said signal will indicate stop.

8. In combination, a section of railway track intersected by a highway,a track circuit for said section including a track relay, a time elementrelay controlled by a back contact of said track relay, said timeelement relay being provided with a normally closed check ing contactwhich becomes opened as soon as the relay becomes energized and with anormally closed time element contact which remains closed after therelay becomes energized until the expiration of a time interval ofcomparatively long duration, a checking relay controlled by saidchecking contact, a slow releasing signal relay, a circuit for saidsignal relay including said time element contact and a front contact ofsaid track relay, said circuit being provided with a branch around saidfront contact of said track relay including a back contact of saidchecking relay, a highway crossing protective device located at theintersection of said highway and said section and controlled by a backcontact of said signal relay, a distance relay controlled by traflicconditions in advance of said section in such manner that said relay isenergized or deenergized according as traffic conditions in advance aresafe or unsafe, a signal for controlling traffic over said scctioncomprising a proceed lamp, a caution lamp, and a stop lamp; a circuitfor said proceed lamp including a front contact of said track relay, afront contact of said checking relay, and a front contact of saiddistant relay; a circuit for said caution lamp including a front contactof said track relay, a front contact of said checking relay, and a backcontact of said distant relay; a first circuit for said stop lampincluding a back contact of said track relay, and a second circuit forsaid stop lamp including a front contact of said track relay and a backcontact of said checking relay.

9. In combination, a section of railway track intersected by a highway,a track circuit for said section including a track relay, a time elementrelay controlled by said track relay, a highway crossing signal locatedad- 3' acent the intersection of said section and said highway, andmeans for controlling said signal controlled by said track relay andsaid time element relay in such manner that if said time element relayis operating in its normal manner said signal will become energized atthe expiration of a predetermined time interval of comparatively long'duration after a train enters said section but that if said time elementrelay fails to operate in its normal manner said signal will becomeenergized at the expiration of a comparatively short time interval aftera train enters said section.

In testimony whereofI afix my signature.

ALFRED B. HEYES.

